The invention refers to a gas generator, preferably for an inflatable airbag for the protection of vehicle occupants, consisting of a container holding a combustible gas mixture and provided with a closure which opens into a combustion chamber provided with a as outlet in which the gas mixture is ignited by an ignition device.
In a gas generator of said kind which is known from DE 41 35 776 C1, the container contains a liquid gas consisting of a mixture of one or several short-chain hydrocarbons and dinitrogen monoxide as an oxidizing agent, which is injected into the combustion chamber after the initiation of the gas generator and is ignited therein by an ignition device with an ignition charge. Thereby the ignition clouds and the hot combustion gases ignite the liquid gas which vaporizes and volatilizes due to the occurring expansion in the combustion chamber. In the known gas generator, the ignited gas mixture shows an explosion-like reaction so that gas pressure peaks destroying the combustion chamber may occur. Thus, in order to reduce the high reaction velocity, in the known gas generator an inert gas of carbon dioxide and/or xenon is added to the gas mixture in an amount of preferably 10 through 80% in weight.
The known gas generator is not only detrimental because of the high reaction velocity which is only mitigated by the addition of inert gas, but also because of the use of liquid gas which has to evaporate prior to its ignition so that the supply of additional energy is necessesary. Said evaporation is time-consuming. Furthermore, the high concentration of fuel gas results in a very high temperature of the combustion gases, which is an additional risk if leaks should occur.